Disc drive

ABSTRACT

A disk device including a movable portion which supports pivotally and enably to swing a feed screw axis, a thread motor to drive a small gear and the like which engage with a gear interlocked in an end portion of the feed screw axis thereby to rotate the feed screw axis, and a control screw to perform a height control of the movable portion.

TECHNICAL FIELD

[0001] The present invention relates to a disk device in which an angleadjustment of feed screw axis in relation to a base, can be performed.

BACKGROUND ART

[0002] In Japanese Laid Open Patent Hei 11-283253, a disk device isdisclosed in which whole driving unit is performed a height control inrelation to a base as shown in FIG. 1 in order not to lose a drivingforce which is transferred from a driving source to a feed screw axis byperforming the height control when an angle adjustment of feed screwaxis in relation to the base is performed by a control of attachingheight in relation to the base for an end portion of the feed screw(hereinafter refereed to as first prior art).

[0003] Also in Japanese Laid Open Patent Hei 11-224438 a disk device isdisclosed in which one end portion of driving force transferring side isfixed on a base and it has not been performed the height control andonly the other end is performed the height control as shown in FIG. 2(hereinafter refereed to as second prior art).

[0004] Because the disk devices in the prior art are composed asdescribed above, a controlled movable portion in the height controlbecomes larger when the whole driving unit is performed the heightcontrol in relation to the base (the first prior art), it causes aproblem that overall dimensions of the mechanism becomes larger.

[0005] On the other hand in the second prior art, the controlled movableportion can be made smaller on which the height control is performed,however, it causes a necessity that the driving means must be located onthe other side of a height control performed side, and basically one endis fixed and other end is performed the height control to perform theangle adjustment. In this case in order to reduce a discrepancy ofheight along a focusing direction between an optical pick up and a disk,which is caused in connection with the height control, the heightcontrol is performed at an end portion of the disk peripheral side.Because the driving means must be arranged at a center side of the disk,a space to arrange the driving means is required at the vicinity of adisk motor. Especially for a disk changing mechanism in which aplurality of disks are stocked within one device and they aresequentially exchanged to perform a disk reproducing or a diskrecording, there are so many devices in which a reproducing unit isdriven within the device, a mechanism layout design becomes difficultwhen dimension of a mechanism in the vicinity of a disk motor is large.

[0006] At the same time in the second prior art, because the heightcontrol can be performed only at one end portion of the device, thoughthe angle adjustment of feed screw axis in relation to the base can beperformed, the height control at both ends cannot be achieved andthereby it causes a problem that even when the height control for wholescrew axis in relation to the base is required in conjunction with theangle adjustment, it cannot be achieved.

[0007] Further in the second prior art, a shaft bearing member at theheight control side is composed of one shaft bearing block, and it isguided enably to be performed the height control by a shaft bearingsliding block which is fixed on the base, because this guide isstructured by an interlocking of these two, when a clearance betweenthem is large by a fluctuation in tolerance of parts, it causes aproblem that a positioning of the shaft bearing block becomes unstablewhen the shaft bearing block rattles also in a direction other than theheight control in relation to the shaft bearing sliding block.

[0008] The present invention has been made to solve the above describedproblems and it is an object of the invention to provide a disk devicein which the feed screw axis can be accurately positioned as well as theangle adjustment of feed screw axis in relation to a base and the heightcontrol of whole feed screw axis, can be performed without havingscaling up of whole mechanism and without reducing a degree of freedomin designing.

DISCLOSURE OF THE INVENTION

[0009] The disk device in accordance with the present invention includesa movable portion to support pivotally and enably to swing a feed screwaxis; a driving means for the feed screw axis to be rotated by driving agear which engages with a gear interlocked at an end portion of heightcontrol side of the feed screw axis; and a control means to control aheight of the movable portion.

[0010] By this arrangement an effect can be produced that an angleadjustment of the feed screw axis and a height control of whole feedscrew axis in relation to the base is made possible to be achieved andat the same time the feed screw axis is accurately positioned withouthaving a scale up of whole mechanism and without reducing a degree offreedom in designing.

[0011] The disk device in accordance with the present invention includesa shaft center of gear which is arranged such that it is located in thesame height of a middle point in a range of the height control by theheight control means and it is located on a line perpendicular to adirection of the height control by the height control means.

[0012] By this arrangement an effect can be produced that a drivingforce from a driving means is made surely to be transferred to the feedscrew axis because a variation of gear distance can be minimized whenthe feed screw axis is performed the height control and an engagement ofgears within a range of the height control can always be maintained.

[0013] The disk device in accordance with the present invention includesa holding portion which is fixed on the base to support the movableportion in the height direction and at the same time to regulate apositioning of the feed screw axis in a direction perpendicular to theaxial direction and a height direction.

[0014] By this arrangement an effect can be produced that accuracy ofpositioning for the feed screw axis is raised.

[0015] The disk device in accordance with the present invention includesa swinging axis which is arranged on the movable portion for the movableportion to swing around an axis parallel to an axial direction of thefeed screw axis and to support the swinging axis enably to swing.

[0016] By this arrangement an effect can be produced that a degree offreedom in designing for mechanism arrangement can be raised because itis made possible to easily change an arrangement of the control means.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017]FIG. 1 is a perspective view to show a disk device in the priorart.

[0018]FIG. 2 is a perspective view to show a disk device in the priorart.

[0019]FIG. 3 is a perspective view to show whole optical head drivingmechanism including a feed screw axis height control mechanism of a diskdevice according to embodiment 1 of the present invention when lookingfrom back side.

[0020]FIG. 4 is an exploded perspective view to show the disk deviceshown in FIG. 3.

[0021]FIG. 5 is a perspective view to show a driving means and a gear.

[0022]FIG. 6 is a perspective view to show how to attach the drivingmeans and the gear onto a base shown in FIG. 5.

[0023]FIG. 7 is a side view of FIG. 6 when looking from Y direction.

[0024]FIG. 8 is a perspective view to show an arrangement of gears totransfer a driving force from a driving means to a feed screw axis.

[0025]FIG. 9 is a perspective view to show a height control mechanism ofthe feed screw axis.

[0026]FIG. 10 is an exploded perspective view of FIG. 9.

[0027]FIG. 11 is a perspective view of relevant part to show the heightcontrol mechanism of feed screw axis.

[0028]FIG. 12 is an exploded perspective view to show the height controlmechanism of feed screw axis.

[0029]FIG. 13 is a side view of FIG. 12 when looking from Y direction.

BEST MODE FOR CARRYING OUT THE INVENTION

[0030] For explaining the present invention in more detail, best modesfor carrying out the invention will be described hereinafter withreference to the accompanied drawings.

Embodiment 1

[0031]FIG. 3 is a perspective view to show whole optical head drivingmechanism including a feed screw axis height control mechanism of a diskdevice according to embodiment 1 of the present invention when lookingfrom back side, FIG. 4 is an exploded perspective view to show the diskshown in FIG. 3, FIG. 5 is a perspective view to show a driving meansand a gear, FIG. 6 is a perspective view to show how to attach thedriving means and the gear onto a base shown in FIG. 5, FIG. 7 is a sideview of FIG. 6 when looking from Y direction, FIG. 8 is a perspectiveview to show an arrangement of gears to transfer a driving force from adriving means to a feed screw axis, FIG. 9 is a perspective view to showa height control mechanism of the feed screw axis and FIG. 10 is anexploded perspective view of FIG. 9. At this point directions X, Y and Zdesignated in these respective drawings are set to be common in theserespective drawings.

[0032] In FIG. 3 and FIG. 4 a reference numeral 10 designates a base, 11designates a disk motor which is fixed on the base 10 by locking screws12 a, 12 b, 12 c via supporting tables 13 a, 13 b, 13 c which are fixedon the base 10 by a manner caulking and the like, 12 a, 12 b, 12 cdesignate locking screws, 13 a, 13 b, 13 c designate the supportingtable which are fixed on the base 10, 20 designates a guiding axis, 21designates a feed screw axis which movably supports an optical pick up31 along a radial direction of the disk as well as the guiding axis 20,22 designates a shaft bearing which is fixed by the locking screw 23 onthe base 10 to support enably to swing an end portion 21 b of the feedscrew axis 21.

[0033] A reference numeral 23 designates a locking screw, 24 designatesa leaf spring which contacts with the end portion 21 b of the feed screwaxis 21 at tip end portion 24 a to urge the feed screw axis 21 along itsaxis direction, 25 designates a holding portion which regulates apositioning of the feed screw axis 21 in a direction perpendicular tothe axial direction and a height direction, 26 designates a movableportion which supports pivotally and enably to swing the feed screw axis21, 27 designates an elastic member which is arranged at a hole portion25 a of the holding portion 25 to energize the movable portion 26 in Z(+) direction, 28 designates a gear which is made to be interlocked atan end portion 21 a of the feed screw axis 21, 29 designates a lockingscrew, and 30 designates a control screw which engages with a tapportion made on the base 10 and is arranged at a position where a tipportion 30 a contacts with the movable portion 26, the control screw 30consists the control means that controls a height of the movable portion26.

[0034] A reference numeral 31 designates an optical pick up which movesalong a radial direction of the disk when the feed screw axis 21 isrotated, 32 designates a leaf spring whose nut portion 32 a engages witha leading screw (not shown) made on the feed screw axis 21 for theoptical pick up 31 to be moved along the radial direction of disk by arotation of the feed screw axis 21, 33 designates an urging spring whichis fixed on the optical pick up 31 by locking screws 34, 35 to movealong the radial direction of disk in a manner contacting with theguiding axis 20, and 34, 35 designate locking screws.

[0035] In FIG. 5 a reference numeral 40 designates a thread motor(driving means) which is fixed on a gear base 41 by locking screws 42 a,42 b for the feed screw axis 21 to be rotated by the gears, 42 a, 42 bdesignate locking screws, 43 designates a worm gear which is fixed on ashaft 40 a of the thread motor 40, 44 designates gears which aresupported by a supporting shaft 47 fixed on the gear base 41, in which ahelical gear portion 44 a engages with the worm gear 43, a flat gearportion 44 b engages with a large gear 45 a of the gears 45, 45designates gears which are pivotally supported by a supporting axis 46fixed on the gear base 41, 46 and 47 designate the supporting axes.

[0036] At this point the holding portion 25 shown in FIG. 9 and FIG. 10,is fixed on the base 10 by the locking screw 29. The movable portion 26rotatably and pivotally supports the end portion 21 a of feed screw axis21 by a hole portion 26 a to regulate the height along Z direction.

[0037] Protruding portions 26 b, 26 c of the movable portion 26 engagewith cut portion 25 b, 25 c of the holding potion 25, and protrudingportions 26 d, 26 e, 26 f, 26 g (not shown) of the movable portion 26,which respectively protrude in Y direction, are made having a relationin dimension by which they engage with cut portions 25 d, 25 f of theholding portion 25, thereby the movable portion 26 is movably supportedalong Z direction by the holding portion 25. At this point the cutportion 25 d, 25 f regulate a positioning of the end portion 21 a offeed screw 21 along X direction and support it rotatably and pivotally.

[0038] On the other hand the thread motor and the gears which aresupported by the gear base 41, are fixed on the base 10 by locking screw48 as shown in FIG. 3 and FIG. 4. At this point a shaft center of thegear 45 is located about a middle point in a range of the height controlof the feed screw axis 21 and at the same time it is located on a lineperpendicular to a direction of the height control as shown in FIG. 8.By this arrangement a small gear 45 b and the gear 28 are made to beengaged together to transfer a driving force from the thread motor 40 tothe feed screw axis 21.

[0039] Hereinafter operation of the disk device will be explained.

[0040] A height along Z direction of the end portion 21 a of feed screwaxis 21 which is supported enably to go up and down along Z direction inrelation to the holding portion 25 is defined to position by a heightalong Z direction of the movable portion 26.

[0041] By tightly fastening the control screw 30, the movable portion 26moves to Z (−) direction with resisting an urging force in Z (+)direction by the elastic member 27. On the other hand when loosing thecontrol screw 30, the movable portion 26 moves to Z (+) direction by theurging force of elastic member 27.

[0042] By this arrangement a height control of the end portion 21 a offeed screw 21 along Z direction can be realized. In connection with thiscontrol the gear 28 fixed on the end portion 21 a is also displaced in Zdirection. Accordingly a gear distance between the gear 28 and the smallgear 45 b is varied, however, this variation of gear distance can beminimized by an arrangement that a central axis of the small gear 45 bis positioned such that it is located about the middle point within arange of the height control of feed screw axis 21 and located on a lineperpendicular to the direction of height control. Even in a case whenthe range of height control is so small in comparison with the geardistance, it is made possible to transfer the driving force withoutheight adjustment of the thread motor 40 or the gears to transfer thedriving force because an engagement of gears can be kept even inrelation to the distance variation.

[0043] Also a positioning of the end portion 21 a of feed screw axis 21along Z direction is regulated by the movable portion 26 as describedabove. On the other hand a positioning along X direction is regulated bythe cut portions 25 d, 25 f which are arranged on the holding portion 25fixed on the base 10, thereby it is made possible to decide positionwithout effected by an operation of the control for the movable portion26 along Z direction.

[0044] As it becomes apparent by the above description, a disk device inaccordance with the Embodiment 1 of present invention brings about aneffect that a number of parts which must be moves for the height controlcan be reduced, and thereby whole dimension of mechanism can beminimized by means that the height control mechanism of feed screw axis21 are made as described above.

[0045] At the same time the disk device also brings about an effect thata degree of freedom in designing for mechanism arrangement can be raisedbecause it is made possible to arrange the thread motor 40 in a sameside with the height control side. Further, because it is made possiblethat the height control is performed at both ends of the feed screw axis21, it brings about an effect that the height control of whole feedscrew axis 21 in relation to the base 10 can be achieved in time withthe angle adjustment.

[0046] Yet further because the positioning of feed screw axis 21 along Xdirection can be performed without influenced by the control operationof movable portion 26 along Z direction, it brings about also an effectthat accuracy of positioning for the feed screw axis 21 along Xdirection can be raised.

Embodiment 2

[0047]FIG. 11 is a perspective view of relevant part to show the heightcontrol mechanism of feed screw axis, FIG. 12 is an exploded perspectiveview to show the height control mechanism of feed screw axis and FIG. 13is a side view of FIG. 12 when looking from Y direction. Because thesame reference numerals those used in FIG. 1 to FIG. 10 designate thesame or the equivalent parts, further explanation on them will beomitted.

[0048] As shown in FIG. 12 the movable portion 26 has a swinging axis 26h which is arranged substantially parallel to a direction of the feedscrew axis 21 and the swinging axis 26 h engages with a hole portion 25h made on the holding portion 25. The holding portion 25 supports themovable portion 26 enably to swing around the swinging axis 26 h. Areference symbol 26 i designates a protruding portion made on themovable portion 26, it is arranged at a position at which it contactswith the tip portion 30 a of control screw 30.

[0049] Hereinafter an operation of the disk device will be explained.

[0050] A height along Z direction of the end portion 21 a of feed screwaxis 21 is defined to position by a height along Z direction of themovable portion 26 which is supported enably to swing around theswinging axis 26 h in relation to the holding portion 25.

[0051] By tightly fastening the control screw 30, the movable portion 26moves with rotation to Z (−) direction with resisting the urging forcein Z (+) direction by the elastic member 27. On the other hand whenloosing the control screw 30, the movable portion 26 moves with rotationto Z (+) direction by the urging force of elastic member 27.

[0052] By this arrangement a height control of the end portion 21 a offeed screw 21 along Z direction can be realized. At this point aposition of the control screw 30 can be arbitrary arranged by means ofchanging a position of the protruding portion 26 i which contacts withthe control screw 30 as far as it is included within an area where themovable portion 26 can swing.

[0053] Also a positioning of the end portion 21 a of feed screw axis 21along Z direction is regulated by the movable portion 26 as describedabove. On the other hand a positioning along X direction is regulated bythe cut portions 25 f which is arranged on the holding portion 25 fixedon the base 10, thereby it is made possible to decide position withouteffected by an operation of the control for the movable portion 26 alongZ direction.

[0054] As it becomes apparent by the above description, the disk devicein accordance with the Embodiment 2 of present invention brings about aneffect that a degree of freedom in designing for mechanism arrangementcan be raised because it is made possible to easily change anarrangement of the control screw 30 in addition to the effect given bythe above described Embodiment 1.

Industrial Applicability

[0055] As set forth above, the disk device in accordance with thepresent invention is suitable for a disk device in which it is requiredto prevent a scaling up of whole mechanism when the mechanism to achievethe angle adjustment of feed screw axis in relation to the base isinstalled.

What is claimed is:
 1. A disk device comprising: a feed screw axis tomovably support an optical pick up along a radial direction of disk; amovable portion to support pivotally and enably to swing said feed screwaxis; a driving means for said feed screw axis to be rotated by drivinga gear which engages with a gear interlocked at an end portion of heightcontrol side of said feed screw axis; and a control means to control aheight of said movable portion.
 2. The disk device according to claim 1characterized by that a shaft center of the gear which is driven by saiddriving means, is arranged such that it is located in the same height ofa middle point in a range of the height control by the height controlmeans and it is located on a line perpendicular to a direction of theheight control by said height control means.
 3. The disk deviceaccording to claim 1 characterized by that a holding portion whichregulates a positioning of the feed screw axis in a directionperpendicular to the axial direction and a height direction while theholding portion movably supports the movable portion in the heightdirection, is fixed on the base.
 4. The disk device according to claim 1characterized by that a swinging axis for the movable portion to swingaround an axis parallel to an axial direction of the feed screw axis, isarranged on said movable portion and the holding portion supports theswinging axis enably to swing.